AI 中文总结
该研究提出统一框架分析多驱动蒸汽中量子可观测量，利用密度矩阵形式和SW维格纳函数，揭示可观测量间关系，分离多普勒奇数分量得量子关联见证，共振荧光成热鲁棒可观测量，实现抗多普勒量子传感和精密场电测。
AI 中文摘要
我们提出了一个统一的、几何分辨的框架，用于分析多普勒展宽的四能级原子蒸汽中的吸收、共振荧光、纠缠负性和相空间准概率。使用具有热速度平均和精确修饰态对角化的密度矩阵形式，我们表明这些可观测量构成了由多光子干涉支配的共同相干驱动相空间结构的互补投影。该框架的核心是斯特拉托诺维奇-韦尔（SW）维格纳函数，它提供了一个包含布居和相干的统一相空间表示。直接比较揭示了SW准概率分布与纠缠景观之间几乎一一对应的关系，几何相关特征，包括双曲线色散渐近线和分裂共振峰，始终得以保留。此外，分离多普勒奇数分量产生了一个无特征值的代理，它捕获了纠缠负性背后的相干几何，提供了一个非侵入性的量子关联见证。同时，共振荧光成为一个热鲁棒的可观测量：与基于磁化率的吸收不同，其加法极点加权在强驱动下保留了尖锐的奥特勒-汤斯光谱特征。这种鲁棒性使荧光能够在严重的多普勒退相情况下准确跟踪明亮的修饰态和纠缠极值，确立了其作为灵敏电测探针和关联见证的双重作用。通过将相干分辨描述与多普勒敏感的相空间表示相结合，所提出的框架提供了一种实验上可实现的、无特征值的量子态表征方法，实现了基于荧光的抗多普勒量子传感和热原子介质中的精密场电测。
英文摘要
We present a unified, geometry-resolved framework for analyzing absorption, resonance fluorescence, entanglement negativity, and phase-space quasiprobability in Doppler-broadened four-level atomic vapor. Using a density-matrix formalism with thermal velocity averaging and exact dressed-state diagonalization, we show that these observables constitute complementary projections of a common coherence-driven phase-space structure governed by multiphoton interference. Central to this framework is the Stratonovich-Weyl (SW) Wigner function, which provides a unified phase-space representation incorporating both populations and coherences. Direct comparison reveals a near one-to-one correspondence between SW quasiprobability distributions and entanglement landscapes, with geometry-dependent features, including hyperbolic dispersion asymptotes and split resonance ridges, consistently preserved. Furthermore, isolating the Doppler-odd component yields an eigenvalue-free proxy that captures the coherence geometry underlying entanglement negativity, providing a non-invasive quantum correlation witness. At the same time, resonance fluorescence emerges as a thermally robust observable: unlike susceptibility-based absorption, its additive pole weighting preserves sharp Autler-Townes spectral features under strong driving. This robustness enables fluorescence to accurately track bright dressed states and entanglement extrema despite severe Doppler dephasing, establishing its dual role as a sensitive electrometry probe and correlation witness. By combining a coherence-resolved description with a Doppler-sensitive phase-space representation, the proposed framework offers an experimentally accessible, eigenvalue-free approach to quantum state characterization, enabling Doppler-resilient fluorescence-based quantum sensing and precision field electrometry in warm atomic media.
Comments23 pages, 9 figures
